1. Field of the Invention
The present invention relates to a single-lens reflex camera having a plurality of image pickup devices, and more particularly, to a single-lens reflex camera having a so-called live-view display function (also called “through screen display function” or “electronic viewfinder function”).
2. Description of the Related Art
With conventional digital cameras, a user or photographer view a subject image through an optical viewfinder. Recently, digital cameras have been proposed which present a live-view display without an optical viewfinder or present a live-view display with an optical viewfinder equipped and using the output of an image pickup device.
For example, Japanese Patent Laid-Open No. 2000-175100 discloses a digital single-lens reflex camera in which a sub image pickup device for shooting a moving picture is removably mounted in a finder optical path in addition to a main image pickup device for recording still picture data. With the sub image pickup device mounted, the digital single-lens reflex camera can display a live-view on a display device based on the output of the sub image pickup device. The digital camera is a single-lens reflex camera of a type which switches the optical path for the light beam of a subject either to the main image pickup device for recording a still picture or the optical viewfinder. To observe a subject image on a monitor device of this single-lens reflex camera, it is necessary to move a movable mirror in the finder optical path upward to guide the light beam of the subject toward the image pickup device for recording.